The US president has widely been accused of racism after posting a series of tweets attacking Democratic congresswomen yesterday, in which Mr Trump claimed the women "originally came from countries whose governments are a complete and total catastrophe", before suggesting they "go back".
The messages were aimed at four congresswomen of colour- three of whom were born and raised in the US while the fourth moved to the US as a child.
The politicians - Alexandria Ocasio-Cortez, Rashida Tlaib and Ayanna Pressley, and Ilhan Omar - have all called the president racist.
The First Minister has been a regular critic of Mr Trump's often combative approach to politics. She described some of the comments made by the business tycoon during his successful election campaign as "deeply abhorrent", and expressed her wish he would change his tone in office.
The latest string of controversial tweets from the president follows days of headlines in the US regarding immigration at the southern border. Last week Ms Ocasio-Cortez, Ms Tlaib and Ms Pressley testified to a House committee about conditions in a migrant detention centre they had visited, expressing horror over alleged mistreatment happening "under American flags".
In a string of tweets posted yesterday, the president wrote: "So interesting to see 'progressive' Democrat congresswomen, who originally came from countries whose governments are a complete and total catastrophe, the worst, most corrupt and inept anywhere in the world (if they even have a functioning government at all), now loudly and viciously telling the people of the United States, the greatest and most powerful nation on earth, how our government is to be run."
Outgoing prime minister Theresa May called the tweets "completely unacceptable".
"Her view is that the language which was used to refer to the women was completely unacceptable," Ms May's spokesman told reporters today.